Camp stove

ABSTRACT

A CAMP STOVE HAVING SEPARATE BURNERS THAT RECEIVE FUEL FROM SEPARATE VAPORIZING TUBES, BUT WHERE ONE BURNER HEATS BOTH OF THE VAPORIZING TUBES, AND FURTHER HAVING A CONTROL AS BETWEEN TWO BURNERS THAT RECEIVE FUEL MIXTURE FROM THE SAME VAPORIZING TUBE SUCH THAT WHEN THE CONTROL IS CLOSED IT DIRECTS ALL OF THE MIXTURE TO THE SECOND BUT AS IT IS SHIFTED TO ADMIT FUEL MIXTURE TO THE SECOND BURNER IT ALSO THROTTLES THE FUEL MIXTURE PASSAGE TO THE FIRST BURNER SO THAT FUEL MIXTURE IS DIRECTED TO THE BURNERS IN APPROXIMATELY EQUAL QUANTITIES WHEN THE CONTROL IS FULLY SHIFTED.

J. W. SPOTTS Feb. 6, 1973 CAMP STOVE Filed April 20, 1971 INVENTOE d A//a/e 6700776 @XML ATTY.

United States Patent @flic-e 3,714,938 Patented Feb. 6, 1973 3,714,938 CAMP STOVE I. Willard Spotts, Huntsville, Mo., assigner to McGraw-Edison Company, Elgin, Ill. Filed Apr. 20, 1971, Ser. No. 135,617 Int. Cl. F24c 5/20 U.S. Cl. 126-38 9 Claims ABSTRACT F THE DISCLOSURE A camp stove having separate burners that receive fuel from separate vaporizing tubes, but where one burner heats both of the vaporizing tubes; and further having a control as between two burners that receive fuel mixture from the same vaporizing tube such that when the control is closed it directs all of the mixture to the first burner but as it is shifted to admit fuel mixture to the second burner it also throttles the fuel mixture passage to the first burner so that fuel mixture is directed to the burners in approximately equal quantities when the control is fully shifted.

Camp stoves frequently burn an unleaded gasoline or other low Volatility liquid petroleum product, which must be vaporized before it burns smoothly in a controlled manner. Consequently, a vaporizing tube commonly is held close to the actual burner Iiiarne and the liquid fuel is passed through the tube and heated to a temperature suflicient to become a gas. This gas fuel is then mixed in a carburetor with air for common discharge as a combustible mixture from the burner, and a control valve located upstream of the vaporizing tube typically at the fuel tank adjusts the heat output of the burner. To have the vaporizing burner and another operate simultaneously off the same vaporizing tube, a pipe commonly connects the carburetor also with a secondary burner and part of the total gas mixture is bled off as regulated by a control valve in the pipe. Since generally the run from the carburetor to the secondary burner is longer than from the carburetor to the vaporizing burner, the resulting greater pressure drop keeps the secondary burner output lower than the vaporizing burner output.

This invention discloses, and an object of the invention is to provide, an improved diverting control system between the carburetor and the vaporizing and secondary burners such that each passage between the carburetor and the respective burner changes in area progressively as the relative outputs of the burners are changed through the adjustment of the control, effective to make the burner outputs more nearly equal if such is desired.

Another common defect in existing camp stoves :is 'the inadequate number of burners, frequently two burners or possibly three. This means that for larger families or greater demands, more than one stove must be used. l

This invention describes, and another object of this invention is to provide, a camp stove having four burners where two control valves and two vaporizing tubes are utilized each to feed a pair of burners, but where each vaporizing tube is vheated by the same vaporizing burner. This eases the manner of starting all other burners, and since the second burner ignited in use would be the other vaporizing burner, the arrangement provides independently controlled maximum heat outputs for the first two operating burners. Should three or four burner operation be desired, a diverter valve in accordance with the iirst' feature of the invention can be provided.

These and other objects of this invention will be more fully understood and appreciated after referring to the following specification, the accompanying drawing forming a part thereof, wherein:

FIG. 1 is a perspective view of the subject camp stove showing part of the components broken away for clarity of disclosure;

FIG. 2 is a sectional view as seen generally from line 2 2 in FIG. l, showing details of construction of the carburetor, diverter valve mechanism, and the vaporizing tube arrangement; and

FIG. 3 is a top plan view of the burner shown in FIG. 2.

Referring to FIG. 1 of the drawing, the camp stove 10 shown has a sheet metal case 12 of box-like construction having a bottom Wall 13, a front wall 14, a rear wall 15, and opposed side walls 16 and 17, and a cover 18 is hinged along the upper edge of the rear wall 15 to close the case in a known manner suitable for traveling. The case has mounted therein four burners being identified as front vaporizing burner 20, front secondary burner 21, rear vaporizing burner 22 and rear secondary burner 23. Each of the burners is supported from the bottom wall by means of a sheet metal foot or bracket typically shown at 25. A grating 27 formed of strong metal rods or the like is adapted to be removably supported adjacent the upper edge of the case 12 in overlying spaced relation to the burners for supporting cookware over the burner flame.

A fuel tank 30 is removably mounted by hook means or the like (not shown) relative to the front wall 14 of the case, and a valve block 32 on the fuel tank has a pair of components 33 and 35 communicating between the fuel tank and respective vaporizing tubes 34 and 36 ex tended from the valve block in general overlying relation to the burner 20. The free ends of the vaporizing tubes each has a nozzle 38 of typical construction for discharging a jet of vaporized fuel and this nozzle lits through an opening in the near side wall of a carburetor mixing device. Two carburetor devices 40 and 42 are used, being located side by side for the respective vaporizing tubes 34 Iand 36, and pipe 44 connects the carburetor 40 to the burner 20 and pipe 46 connects the carburetor 42 to the burner 22.

The carburetors are in effect an inverted cup having a solid top wall, an inlet opening for the fuel nozzle in one side wall, a pipe outlet opening to the burner in another side wall, and an opening in either the bottom wall or a remaining side wall for admitting air to provide a proper combustible mixture. Specifically, the devices might be formed of sheet metal stampings each having an enlarged flared open end 47 and the appropriate openings in the side walls for removably receiving the nozzle and for receiving the pipe which can be welded thereto. The device 40 utilizes the open end at the bottom for an air inlet, with a slide plate 48 adjustably covering the same to achieve a richer mixture as required particularly for cold starting. The device 42 has a solid closure plate 49 over the open end which is now located at the top, and the devices can be secured together in a side by side manner. Another opening 50 then can be punched or drilled in the last open side wall to serve as lthe air inlet, and a dimpled plate 51 is hinged at pin 52 adjacent the sidewall to adjustably cover the opening to regulate the fuel air mixture.

Each burner has a cup shaped manifold 60 where plate 62 closes the top of the manifold except for opening 64 and an annular piece 66 and cover 67 are fitted over upstanding ring 65 on the plate and held in place by a screw 68 threaded into the manifold structure. The opening 64 permits passage of the combustible gas mixture within the burner manifold for discharge through jets in the annular piece 66 to over the upwardly cupped burner plate 63 above which a flame develops. Fuel mixture pipe 44 is connected to the manifold of burner 20, while pipe 46 is connected to the manifold of burner 22; and diverter pipes 69 and 70 are connected between the manifolds of the front burners and 21, and the rear burners 22 and 23 respectively. Thus, vaporizing tube 34 operates through carburetor 40 to provide fuel for burners 20 and 2l, while vaporizing tube 36'operates through carburetor 42 to provide fuel for the burners 22 and 23.

The particular control for operating either of the secondary burners 21 or 23 will now be disclosed. It can be noted from FIGS. 3 and 4 that the typical diverter pipe extends into the burner manifold a limited distance and is provided with an annular seat 71 at its open end. A diverter control element 72 is supported at the end of rod means 73 extended through an opening in the manifold wall and a slotted opening 74 in the case side wall 16. The element 72 has a flat face 75 which is sufficiently large to completely close the open pipe end when it engages the seat 71 which then stops fuel mixture passage to the connected secondary burner. The element 72 also has a laterally extending leg 77 adjacent the underside of burner plate 62, the leg having a keyhole shaped opening 78 which is aligned generally under the inlet opening 64 when the face is against the seat to provide the largest effective passage between the manifold and the primary burner through the openings 78 and 64. The rod means 73 is preferably of two telescoping pieces 80 and 81 which are connected to the element 72 and to an actuating handle 82 respectively, and a spring 84 is confined between the telescoped pieces tending to separate them from one another. The outer piece 81 further is provided with a groove 90 which can fit .into the slot of case opening 74 to hold the element 72 snugly against the seat and thereby close off the secondary burner.

To operate the secondary burner, the outer rod 8 1 is disengaged from the case wall and shifted outwardly to uncover the open end 71 of the diverter pipe to permit fuel mixture to flow to the connected secondary burner. Movement of control element 72 also causes the openings 78 and 64 to become misaligned to reduce the overall effective passage area between the manifold and the primary burner. This control element movement throttles the effective gas passage area to the primary burner while it opens the passage area to the secondary burner, and does so progressively as the element is moved away from the seat 71, until at its opposite position the effective passage areas are approximately equal. This meansl that both burners receive approximately theA same volume of gas mixture to operate at approximately equal outputs.

In operation, the control valve 33 is initially opened which feeds through the carburetor device 40 to the front burner 20 which can be and when ignited heats the vaporizing tube 34 for sustaining vaporized fuel feed to the burner. While the burner 20 is operating, the vaporizing tube 36 is likewise being heated although with the valve closed no fuel will be discharged. Should operation of a second be needed, it would be preferable to then ignite the rear burner 22 upon opening control valve 35 which feeds through the carburetor device 42. Each of the burners 20 and 22 s then controlled independently by the respective control valve. Should a third burner be needed, either of the secondary burners 21 and 23 can be'ignited and regulated by the respective diverter control to where the connected pair of burners can have virtually edual outputs, and likewise for a fourth burner. The fuel tank is typically provided with hand pump means (not shown) to force the liquid gas through the vaporizing tubes under the direct adjustment of the valve means 33 or 35.

What is claimed is:

1. A camp stove comprising a case, first and second 'burners supported in the case and having respective carburetor mixing devices connected thereto, a fuel tank having first and second vaporizing tubes through which fuel can be discharged, first and second control valves for regulating fuel discharge through the respective vaporizing tubes, and means for mounting the fuel tank on the case such that the first and second vaporizing tubes are operatively associated with the respective carburetor mixing devices to discharge fuel thereto and are further disposed in heat receiving proximity to the first burner whereby the first burner heats both the first and second vaporizing tubes, said first burner having a manifold including an outlet opening therefrom to jets of the first p burner, a third burner supported in the case, fuel conveying means connecting the first burner manifold with the third burner, and a flow control located in the manifold operable in one extreme position to close the connecting means and operable upon movement from this one extreme position to progressively open the connecting means and to reduce the effective area of the manifold outlet opening to the first burner jets.

2. A camp stove according to claim 1, wherein the ow control includes a single element having spaced control faces that cooperate with the fuel conveying means and with the manifold outlet opening, respectively.

3. A camp stove comprising a case, first and second burners supported in the case and having respective carburetor mixing devices connected thereto, a fuel tank having first and second veporizing tubes through which fuel can be discharged, first and second control valves for regulating fuel discharge through the respective vaporizing tubes, and means for mounting the fuel tank on the case such that the first `and second vapor-izing tubes are operatively associated with the respective carburetor mixing devices to discharge fuel thereto and are further'disposed in heat receiving proximity to the first burner whereby the first burner heats both the first and second vaporizing tubes third and fourth burners `supported in the case, and fuel conveying means connected between the first and third burners and between the second and fourth burners, respectively, each such fuel conveying means including a flow control operable to regulate the fuel discharge to the respective third or fourth burners as a percentage of the fuel discharge to the first or second burners.

4. A camp stove comprising a case, two burners supported in the case, one of the burners having a manifold including an outlet opening therefrom to jets of the said one burner, fuel conveying means connecting the one burner manifold with the other burner, a flow control located in the manifold operable in one extreme position to close the connecting means and operable upon movement from this one extreme position to progressively open the connecting means and to reduce the effective area of the manifold outlet opening to the one burner jets, a fuel tank having a vaporizing tube through which fue] can be discharged, acontrol valve for regulating fuel discharge extends exteriorly of the manifold and the case operable to be shifted by an operator to move the ow control.

7. A camp stove according to claim 6, wherein said actuator is composed of cooperating telescoping rod elements where one element is connected to to flow control element, a spring tending to separate the rod elements axially, and lock means 0n the other rod element and case which when engaged compresses the spring to shift the flow control to the one extreme position.

8. A camp stove according to claim 5, wherein still a third burner is supported in the case, a carburetor device connected for discharge to the third burner, a second vaporizing tube supported from the fuel tank and a separate control valve for regulating fuel discharge through the second vaporizing tube and the second vaporizing tube being operatively associated with the carburetor device to discharge fuel thereto and being in heat receiving proximity to the said one burner.

9. A camp stove according to claim 8, wherein an actuator is connected to the flow control and extends exteriorly of the manifold and the case operable to be shifted by an operator to move the ow control.

References Cited EDWARD G. FAVORS, Primary Examiner 

